The extension of the corporate network

Although there are a multitude of applications in WiFi technology, it is clear as its primary target is the corporate network. As we have seen, the WiFi was designed for a wireless version of Ethernet and the latter is found in almost all businesses. In most cases, a company that decides be equipped with a WiFi network already has a wired Ethernet network. It is therefore generally build a wireless extension to an existing wired network.

WiFi at home

WiFi has reached the general public and more and more individuals equip themselves WiFi to build a home network. The aim is often to enable the Internet connection from any location in the home, as well as share the connection between family members. Most often, one WiFi terminal is sufficient to cover a home less than 100 m2. In addition, most of Internet service providers (ISPs) offer the WiFi option from 2005: ADSL modem / router (the "box") is then used also WiFi access point.

Another motivation may be to interconnect equipment such as screens or wireless printers. WiFi then impinges on the chosen field Bluetooth technology which has been designed for such use.

Hotspots

Points Wireless Internet access

A hotspot is a wireless Internet access point (or more generally to services web). It is therefore akin to a cafe, except that the client uses to connect their own computer with WiFi technology (or "smartphone" WiFi compatible, like the iPhone for example). This allows it to retain a hotspot to another, the same work environment: his. There are hotspots in many sites where transit businessmen with computers Portable: airports, train stations, hotels, conference centers, but also cafes, restaurants, universities and generally almost any place public. It is also sometimes find them in waiting rooms or meeting within some companies looking to provide their customers or suppliers pass a link accessible and independent Internet in their own network.

Hotspots have emerged as early as 2000, first in the United States, and so viral all over the world and particularly in Southeast Asia where they are in the thousands. In the US, Starbucks coffee chain caused a sensation when equipped hotspots all its cafes. In France, hotspots have began to appear as the end of 2002, where the law allowed. The society Wifirst (formerly known as the Wifix) was the first to deploy hotspots on French territory. Soon she was joined by a many other start-ups, such as Wifispot, Hot Coffee or Metro Networks, then by major players such as Orange, SFR, De Paris Airports (ADP) Telecom, or still Swisscom and British Telecom. These telecom operators of a new kind are called the Wireless Internet Service Providers (WISPs) that is to say Suppliers of Internet access (ISP) wirelessly.

Homelessness (or roaming)

With the rapid emergence of many independent WISP, there has been a fragmentation major hotspot networks. Clearly, when we bought a coupon connection or a subscription to a given WISP, there was general access network at this WISP, that is to say the more often a few tens or Hundreds of hotspots. It is for this problem that WISP sign roaming agreements (or roaming) that allows subscribers of a given supplier to "surf" on the network of another provider.

Community WiFi

WiFi technology owes part of its success to associations such initiatives that Toronto Wireless (formerly WiFi Canada) or WiFi Otava. These associations bring together enthusiasts Wireless who had the idea to work together to attempt to obtain a substantial WiFi coverage on more or less websites scale. The advantage of these networks is their traditional hotspots totally free!

Each member has a small home wireless network, open to all. Some associations only provide a list of sites where you can connect and free, others go further and link the access points, mesh and for sharing Internet connections. This is particularly interesting for the residents of municipalities where ADSL is not available; thus, a single connection to the Internet via satellite (rather expensive) can be distributed over a town with a dense network of WiFi access points.

One of the main concerns about this model is its legality: indeed, in Canada, the owner of an Internet connection is responsible. If the network Community is open to all, without identity control, then an ill person may well intentioned abuse the internet in anonymity more complete. It will then send out thousands of unsolicited emails (spam) make racist or defamatory, incite violence or exchange illegal files (illegal images or videos, commercial products ...). In this case, the owner of the internet can be blamed for not having Protected Access.

Point to Point

With the WLAN, it is possible to construct simple wireless connections from one point to another, broadband. This is useful to connect two locations difficult to reach by wire, as two buildings of a business. The maximum distance between both buildings depends on the flow that is to ensure (the distance will be more greater the rate will be low) and the selected frequency band, but you can to several megabits per second up to 2 to 3 kilometers in direct vision, that is to say without obstacle on the axis or close to the axis between transmitter and receiver.

WiFi in the industry

One proof of the maturity of WiFi is the fact that we used to do more than simple networks industry employs more and more varied applications which based on WiFi. Here are some of the most significant.

Inventories

PDAs, Smartphone or Tablet PCs are equipped with a WiFi connection and thus allow employees to conduct inventories that are recorded in real time in the company's database. This can be useful for inventory of a large area, for example, to save time. There is also the use of WiFi for car rental companies, who can enter directly from the parking cars leaving and returning. Paris airports also use WiFi to check in bags before loading them on planes. This is a crucial point in their security policy because we must always ensure that luggage and their owners are on the same plane.

Positioning

Software installed on PDAs with WiFi enable, measuring the radio signal strength from different neighboring WiFi antennas, position with relative accuracy (less than 2 meters) the holder of the PDA, for a fairly simple initial calibration. This can be put to use in inventories, of course, but also to offer clients a service located. For example, a museum can put this advantage to provide its visitors with information on the works located in the vicinity. The visitor has nothing else to do than wander around the museum provided with its PDA, loaned by the museum for the duration of the visit.

The voice

One of the great promises of WiFi is its ability to manage communications digital audio thanks to VoIP technology (Voice over Internet Protocol, VoIP). When VoIP is performed on a wireless network, sometimes called VoWIP (The "W" comes from Wireless), but the technology is absolutely identical. Already, VoWIP companies offer phones connected to your network via WiFi.

Although the phones in question are still large enough for now and limited autonomy, major advantage is that the cost of communications is extremely low. To join another VoIP phone, the cost is often null. You can easily turn your computer into a phone or PDA By installing a VoIP software such as Skype on your computer. You simply connect a microphone and earpiece on your computer to enjoy it. This type of software allows free calls to other users with the same computer software. In the case of Skype, it is also possible to call to a station classic phone, for a fee.

Sound quality is quite comparable to the traditional fixed telephony if your bandwidth is large and responsive. However, to avoid interruptions in the voice or a time lag too much, it may be necessary implement a QoS policy Quality of Service, (QoS) to ensure that a share of bandwidth is reserved for your communications Phone. This is especially true if you connect to the Internet through your WiFi network, because according to the reception level, throughput and latency may vary significantly.